The invention relates to connecting a die in an integrated circuit module.
In a multi-chip module (MCM), a number of integrated circuit dies and associated discrete chips are placed on a single interconnecting substrate. In this manner, very high pin counts can be achieved internally on the MCM interconnecting substrate, with the MCM package providing fewer output pins than are found internally.
A number of techniques exist to attach the dies to the substrate in an MCM device, including wire bonds, flip chip solder bumps, tape automated bonding leads, and micro-bump bonds. The entire assembly is then packaged using packaging techniques common to single chip modules.
Multi-chip modules can also be fabricated using packages that contain sockets having channels or slots configured to receive bare dies, such as the multi-chip module connector disclosed in U.S. Pat. No. 5,104,324. Such multi-chip modules are referred to as direct die contact (DDC) modules. The sockets in the DDC modules allow the bare dies to be mounted perpendicularly with respect to the interconnecting substrate of the module, thereby achieving higher device density in an MCM. Spring arms are provided in each socket to electrically contact corresponding bond pads of the die inserted into the socket. The spring arms are aligned with respect to the die bond pads in each socket.
With improvement in process technology, die sizes are steadily being reduced. Due to the smaller die sizes, the overall size of the bond pads on each die and the pitch between bond pads are proportionately reduced. This may affect the alignment of the die bond pads to spring arms in the socket of a DDC multi-chip module.